#include "md5.h"

#if UTOOLS_CODE_MD5_ENABLE == 1

#include <cstring>

typedef struct
{
    uint32_t count[2];
    uint32_t state[4];
    uint8_t buffer[64];
} HV_MD5_CTX;

static void HV_MD5Init(HV_MD5_CTX *ctx);
static void HV_MD5Update(HV_MD5_CTX *ctx, uint8_t *input, uint32_t inputlen);
static void HV_MD5Final(HV_MD5_CTX *ctx, uint8_t digest[16]);

#define F(x, y, z) ((x & y) | (~x & z))
#define G(x, y, z) ((x & z) | (y & ~z))
#define H(x, y, z) (x ^ y ^ z)
#define I(x, y, z) (y ^ (x | ~z))
#define ROTATE_LEFT(x, n) ((x << n) | (x >> (32 - n)))
#define FF(a, b, c, d, x, s, ac)  \
    {                             \
        a += F(b, c, d) + x + ac; \
        a = ROTATE_LEFT(a, s);    \
        a += b;                   \
    }
#define GG(a, b, c, d, x, s, ac)  \
    {                             \
        a += G(b, c, d) + x + ac; \
        a = ROTATE_LEFT(a, s);    \
        a += b;                   \
    }
#define HH(a, b, c, d, x, s, ac)  \
    {                             \
        a += H(b, c, d) + x + ac; \
        a = ROTATE_LEFT(a, s);    \
        a += b;                   \
    }
#define II(a, b, c, d, x, s, ac)  \
    {                             \
        a += I(b, c, d) + x + ac; \
        a = ROTATE_LEFT(a, s);    \
        a += b;                   \
    }

static void HV_MD5Transform(uint32_t state[4], uint8_t block[64]);
static void HV_MD5Encode(uint8_t *output, uint32_t *input, uint32_t len);
static void HV_MD5Decode(uint32_t *output, uint8_t *input, uint32_t len);

static uint8_t PADDING[] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

void HV_MD5Init(HV_MD5_CTX *ctx)
{
    ctx->count[0] = 0;
    ctx->count[1] = 0;
    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;
}

void HV_MD5Update(HV_MD5_CTX *ctx, uint8_t *input, uint32_t inputlen)
{
    uint32_t i = 0, index = 0, partlen = 0;
    index = (ctx->count[0] >> 3) & 0x3F;
    partlen = 64 - index;
    ctx->count[0] += inputlen << 3;
    if (ctx->count[0] < (inputlen << 3))
    {
        ctx->count[1]++;
    }
    ctx->count[1] += inputlen >> 29;

    if (inputlen >= partlen)
    {
        memcpy(&ctx->buffer[index], input, partlen);
        HV_MD5Transform(ctx->state, ctx->buffer);
        for (i = partlen; i + 64 <= inputlen; i += 64)
        {
            HV_MD5Transform(ctx->state, &input[i]);
        }
        index = 0;
    }
    else
    {
        i = 0;
    }

    memcpy(&ctx->buffer[index], &input[i], inputlen - i);
}

void HV_MD5Final(HV_MD5_CTX *ctx, uint8_t digest[16])
{
    uint32_t index = 0, padlen = 0;
    uint8_t bits[8];
    index = (ctx->count[0] >> 3) & 0x3F;
    padlen = (index < 56) ? (56 - index) : (120 - index);
    HV_MD5Encode(bits, ctx->count, 8);
    HV_MD5Update(ctx, PADDING, padlen);
    HV_MD5Update(ctx, bits, 8);
    HV_MD5Encode(digest, ctx->state, 16);
}

void HV_MD5Encode(uint8_t *output, uint32_t *input, uint32_t len)
{
    uint32_t i = 0, j = 0;
    while (j < len)
    {
        output[j] = input[i] & 0xFF;
        output[j + 1] = (input[i] >> 8) & 0xFF;
        output[j + 2] = (input[i] >> 16) & 0xFF;
        output[j + 3] = (input[i] >> 24) & 0xFF;
        i++;
        j += 4;
    }
}

void HV_MD5Decode(uint32_t *output, uint8_t *input, uint32_t len)
{
    uint32_t i = 0, j = 0;
    while (j < len)
    {
        output[i] = (input[j]) | (input[j + 1] << 8) | (input[j + 2] << 16) | (input[j + 3] << 24);
        i++;
        j += 4;
    }
}

void HV_MD5Transform(uint32_t state[4], uint8_t block[64])
{
    uint32_t a = state[0];
    uint32_t b = state[1];
    uint32_t c = state[2];
    uint32_t d = state[3];
    uint32_t x[64];

    HV_MD5Decode(x, block, 64);

    FF(a, b, c, d, x[0], 7, 0xd76aa478);
    FF(d, a, b, c, x[1], 12, 0xe8c7b756);
    FF(c, d, a, b, x[2], 17, 0x242070db);
    FF(b, c, d, a, x[3], 22, 0xc1bdceee);
    FF(a, b, c, d, x[4], 7, 0xf57c0faf);
    FF(d, a, b, c, x[5], 12, 0x4787c62a);
    FF(c, d, a, b, x[6], 17, 0xa8304613);
    FF(b, c, d, a, x[7], 22, 0xfd469501);
    FF(a, b, c, d, x[8], 7, 0x698098d8);
    FF(d, a, b, c, x[9], 12, 0x8b44f7af);
    FF(c, d, a, b, x[10], 17, 0xffff5bb1);
    FF(b, c, d, a, x[11], 22, 0x895cd7be);
    FF(a, b, c, d, x[12], 7, 0x6b901122);
    FF(d, a, b, c, x[13], 12, 0xfd987193);
    FF(c, d, a, b, x[14], 17, 0xa679438e);
    FF(b, c, d, a, x[15], 22, 0x49b40821);

    GG(a, b, c, d, x[1], 5, 0xf61e2562);
    GG(d, a, b, c, x[6], 9, 0xc040b340);
    GG(c, d, a, b, x[11], 14, 0x265e5a51);
    GG(b, c, d, a, x[0], 20, 0xe9b6c7aa);
    GG(a, b, c, d, x[5], 5, 0xd62f105d);
    GG(d, a, b, c, x[10], 9, 0x2441453);
    GG(c, d, a, b, x[15], 14, 0xd8a1e681);
    GG(b, c, d, a, x[4], 20, 0xe7d3fbc8);
    GG(a, b, c, d, x[9], 5, 0x21e1cde6);
    GG(d, a, b, c, x[14], 9, 0xc33707d6);
    GG(c, d, a, b, x[3], 14, 0xf4d50d87);
    GG(b, c, d, a, x[8], 20, 0x455a14ed);
    GG(a, b, c, d, x[13], 5, 0xa9e3e905);
    GG(d, a, b, c, x[2], 9, 0xfcefa3f8);
    GG(c, d, a, b, x[7], 14, 0x676f02d9);
    GG(b, c, d, a, x[12], 20, 0x8d2a4c8a);

    HH(a, b, c, d, x[5], 4, 0xfffa3942);
    HH(d, a, b, c, x[8], 11, 0x8771f681);
    HH(c, d, a, b, x[11], 16, 0x6d9d6122);
    HH(b, c, d, a, x[14], 23, 0xfde5380c);
    HH(a, b, c, d, x[1], 4, 0xa4beea44);
    HH(d, a, b, c, x[4], 11, 0x4bdecfa9);
    HH(c, d, a, b, x[7], 16, 0xf6bb4b60);
    HH(b, c, d, a, x[10], 23, 0xbebfbc70);
    HH(a, b, c, d, x[13], 4, 0x289b7ec6);
    HH(d, a, b, c, x[0], 11, 0xeaa127fa);
    HH(c, d, a, b, x[3], 16, 0xd4ef3085);
    HH(b, c, d, a, x[6], 23, 0x4881d05);
    HH(a, b, c, d, x[9], 4, 0xd9d4d039);
    HH(d, a, b, c, x[12], 11, 0xe6db99e5);
    HH(c, d, a, b, x[15], 16, 0x1fa27cf8);
    HH(b, c, d, a, x[2], 23, 0xc4ac5665);

    II(a, b, c, d, x[0], 6, 0xf4292244);
    II(d, a, b, c, x[7], 10, 0x432aff97);
    II(c, d, a, b, x[14], 15, 0xab9423a7);
    II(b, c, d, a, x[5], 21, 0xfc93a039);
    II(a, b, c, d, x[12], 6, 0x655b59c3);
    II(d, a, b, c, x[3], 10, 0x8f0ccc92);
    II(c, d, a, b, x[10], 15, 0xffeff47d);
    II(b, c, d, a, x[1], 21, 0x85845dd1);
    II(a, b, c, d, x[8], 6, 0x6fa87e4f);
    II(d, a, b, c, x[15], 10, 0xfe2ce6e0);
    II(c, d, a, b, x[6], 15, 0xa3014314);
    II(b, c, d, a, x[13], 21, 0x4e0811a1);
    II(a, b, c, d, x[4], 6, 0xf7537e82);
    II(d, a, b, c, x[11], 10, 0xbd3af235);
    II(c, d, a, b, x[2], 15, 0x2ad7d2bb);
    II(b, c, d, a, x[9], 21, 0xeb86d391);

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
}
namespace utools::code
{
    void md5(uint8_t *input, uint32_t inputlen, uint8_t digest[16])
    {
        HV_MD5_CTX ctx;
        HV_MD5Init(&ctx);
        HV_MD5Update(&ctx, input, inputlen);
        HV_MD5Final(&ctx, digest);
    }

    static inline char i2hex(uint8_t i)
    {
        return i < 10 ? i + '0' : i - 10 + 'a';
    }

    void md5_hex(uint8_t *input, uint32_t inputlen, char *output, uint32_t outputlen)
    {
        int i;
        uint8_t digest[16];
        if (outputlen < 32)
            return;
        md5(input, inputlen, digest);
        for (i = 0; i < 16; ++i)
        {
            *output++ = i2hex(digest[i] >> 4);
            *output++ = i2hex(digest[i] & 0x0F);
        }
        if (outputlen > 32)
            *output = '\0';
    }

    const std::vector<uint8_t> md5(std::vector<uint8_t> input)
    {
        std::vector<uint8_t> output(16);
        md5(static_cast<uint8_t *>(input.data()), input.size(), static_cast<uint8_t *>(output.data()));
        return output;
    }

    const std::string md5_hex(std::vector<uint8_t> input)
    {
        char output[33] = {0};
        md5_hex(static_cast<uint8_t *>(input.data()), input.size(), output, 32);
        return std::string(output);
    }
}

#endif // UTOOLS_CODE_MD5_ENABLE